It is known that torque can be measured by measuring the torsional angle or twist of a rotating or stationary shaft which transmits the torque to be measured. The torsion angle which results over a predetermined length of the shaft is a direct measure of the torque and proportional thereto.
Known measuring systems of this type operate by means of optical, capacitive of inductive units which, however, are sensitive to dirt, oil, temperature changes, and the like.